A molded structure body used for a door trim includes a base member containing a thermoplastic resin and a molded member such as a bracket. The molded member is connected to the base member and a thermoplastic resin is injection molded with the base member. Accordingly, the molded member is molded with the base member. In this technology, a connection portion of the base member that is connected to the molded member has a reduced density and this allows melted resin of the molded member to penetrate the connection portion easily. This increases bonding strength due to the anchoring effect caused in the molded member and the connection portion.
In the related art, as illustrated in FIG. 5, a base member 3 is pressed in a molding tool 1 and melted resin is injected into a cavity C1 that is formed in the molding tool 1 as a molding space. Accordingly, the molded member is molded. In a condition that the base member 3 is pressed in the molding tool 1, a surrounding portion around a connection portion 4 of the base member 3 that is connected to the melted resin is in contact with a mold surface 1A of the molding tool 1.
However, in the above structure, when the melted resin is injected into the cavity C1, the melted resin may reach or leak to the surrounding portion 5 around the connection portion 4 of the base member 3 as illustrated in FIG. 5. The melted resin may penetrate a quite small gap between the base member 3 and the mold surface 1A in the surrounding portion 5 or the low density of the connection portion 4 of the base member 3 allows the melted resin to easily penetrate the surrounding portion 5 around the connection portion 4. Accordingly, the melted resin may penetrate inside of the base member 3 along a surface thereof and emerge from a surface of the surrounding portion 5.
If the melted resin used for molding the molded member 6 reaches the surrounding portion 5 around the connection portion 4 in the base member 3, a connection area between the base member 3 and the molded member 6 may increase. Therefore, if the injected melted resin of a molded object is cooled down and contracts, a recess or a projection may be formed on a surface 3A of the base member 3 that is opposite to the surface having the connection portion 4. As illustrated in FIG. 6, a projection 3B is formed, and this deteriorates design.